Effect of inclined jet on heat/mass transfer for impingement/effusion cooling system

Sung Kook Hong, Dong Ho Rhee, Hyung Hee Cho

Research output: Contribution to journalArticle

1 Citation (Scopus)

Abstract

An experimental investigation was conducted to investigate the heat/mass transfer for impingement/effusion cooling system with inclined jet. Jets with inclined angle of 60 are applied to impingement/effusion cooling. At the jet Reynolds number of 10,000, the experiments were carried out for blowing ratios ranging from 0.0 to 1.5. The local heat/mass transfer coefficients on the effusion plate are measured using a naphthalene sublimation method. The result indicates that the inclined jet causes the non-uniform and low heat/mass transfer compared to the vertical jet. At stagnation region, the peak position is shifted from the geometrical center of injection hole due to Coanda effect and its level is higher than that of vertical jet due to increase in turbulence intensity by steep velocity gradient near the stagnation region. Further, the secondary peak region disappears because the interaction between adjacent wall jets weakens. When the initial crossflow occurs, the distorted heat/mass transfer pattern appears. As the blowing ratio (crossflow rate) increases, the heat/mass transfer distributions become similar to those of the vertical jet. This is because the effect of crossflow is dominant compared to that of inclined jet under high blowing ratio (M≥1.0). At low blowing ratio (M≤0.5), averaged Sh value is 10% lower than that of vertical jet, whereas its value at high blowing ratio (M≥ 1.0) is similar to that of vertical jet.

Original languageEnglish
Pages (from-to)283-289
Number of pages7
JournalTransactions of the Korean Society of Mechanical Engineers, B
Volume32
Issue number4
DOIs
Publication statusPublished - 2008 Apr 1

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Cooling systems
Mass transfer
Blow molding
Hot Temperature
Sublimation
Naphthalene
Reynolds number
Turbulence
Cooling

All Science Journal Classification (ASJC) codes

  • Mechanical Engineering

Cite this

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abstract = "An experimental investigation was conducted to investigate the heat/mass transfer for impingement/effusion cooling system with inclined jet. Jets with inclined angle of 60 are applied to impingement/effusion cooling. At the jet Reynolds number of 10,000, the experiments were carried out for blowing ratios ranging from 0.0 to 1.5. The local heat/mass transfer coefficients on the effusion plate are measured using a naphthalene sublimation method. The result indicates that the inclined jet causes the non-uniform and low heat/mass transfer compared to the vertical jet. At stagnation region, the peak position is shifted from the geometrical center of injection hole due to Coanda effect and its level is higher than that of vertical jet due to increase in turbulence intensity by steep velocity gradient near the stagnation region. Further, the secondary peak region disappears because the interaction between adjacent wall jets weakens. When the initial crossflow occurs, the distorted heat/mass transfer pattern appears. As the blowing ratio (crossflow rate) increases, the heat/mass transfer distributions become similar to those of the vertical jet. This is because the effect of crossflow is dominant compared to that of inclined jet under high blowing ratio (M≥1.0). At low blowing ratio (M≤0.5), averaged Sh value is 10{\%} lower than that of vertical jet, whereas its value at high blowing ratio (M≥ 1.0) is similar to that of vertical jet.",
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Effect of inclined jet on heat/mass transfer for impingement/effusion cooling system. / Hong, Sung Kook; Rhee, Dong Ho; Cho, Hyung Hee.

In: Transactions of the Korean Society of Mechanical Engineers, B, Vol. 32, No. 4, 01.04.2008, p. 283-289.

Research output: Contribution to journalArticle

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